Re: [squid-users] Trying to improve the Byte Hit Ratio, any tips ?

Hello squid users, I am green when the word squid comes. I have a box
running suse 10.3 and i need someone to help me configure squid well.
am green at this. Please someone with a few minutes to help me, i will
be glad

On 1/6/09, Amos Jeffries <squid3_at_treenet.co.nz> wrote:
> Vianney Lejeune wrote:
>> Hello,
>>
>> I'm trying to improve the Byte Hit Ratio of SquidCache on my
>> network. There is 220 computers in the LAN, using internet on a general
>> usage basis. The maximum bandwidth is 4Mbps in/out, the total amount of
>> data is estimated to be 30 to 60 Gbytes daily.
>>
>>
>> This is the report from cachemgr:
>> =>
>> Average HTTP requests per minute since start: 1023.9
>> Average ICP messages per minute since start: 0.0
>> Select loop called: 1208577 times, 5.619 ms avg
>> Cache information for squid:
>> Request Hit Ratios: 5min: 37.9%, 60min: 41.1%
>> Byte Hit Ratios: 5min: 13.2%, 60min: 13.8% (It's quite low, these
>> values are usual)
>> Request Memory Hit Ratios: 5min: 2.0%, 60min: 2.6% (I rebooted
>> the server 3 hours ago, this can explain these low values)
>> Request Disk Hit Ratios: 5min: 41.3%, 60min: 36.3%
>> Storage Swap size: 27654312 KB
>> Storage Mem size: 190364 KB
>> Mean Object Size: 29.65 KB
>> Requests given to unlinkd: 33035
>> Median Service Times (seconds) 5 min 60 min:
>> HTTP Requests (All): 0.23230 0.46965
>> Cache Misses: 0.35832 0.72387
>> Cache Hits: 0.19742 0.35832
>> Near Hits: 0.20843 0.55240
>> Not-Modified Replies: 0.03829 0.05331
>> DNS Lookups: 0.00094 0.00779
>> ICP Queries: 0.00000 0.00000
>> <=
>>
>> This is my squid.conf file:
>> =>
>>
>> http_port 3128 transparent
>> hierarchy_stoplist cgi-bin ?
>
>> acl QUERY urlpath_regex cgi-bin \?
>> cache deny QUERY
>
> Without cache peers you can drop the above QEURY acl.
> That will raise both hit ratios on semi-dynamic objects.
> BUT, see addition to refresh_pattern below...
>
>> acl apache rep_header Server ^Apache
>> broken_vary_encoding allow apache
>> maximum_object_size 128 MB
>
> Re: the above maximum. There may be huge objects going through that can
> be cached.
>
> > cache_mem 250 MB
>> maximum_object_size_in_memory 50 KB
>
> memory, memory, memory. The more you can throw at the problem the more
> objects can be kept and served while hot. Squid with 64-bit can easily
> handle many GBs of memory cache. (at cost of slow shutdown when it saves
> the hottest to disk for the next round.)
>
>> cache_replacement_policy heap LFUDA
>
> Been a while since I looked at these, to maximize bytes you want the
> policy that looks at object size as well as 'coldness'. To remove the
> smaller cool objects before the larger equally cool ones.
>
>> cache_dir ufs /data/spool/squid 30000 16 256
>
> Your cache dir is only 30GB. Thats one days traffic or less by your
> above statements. For good hit ratios you may need at least 7 days,
> preferrably as close to 30 as possible.
>
> Depending on your OS, AUFS(Linux) or diskd(*BSD) may prove much faster
> access than UFS.
>
>> access_log none
>> cache_log none
>
> The above is generating log file named "none". Would be more useful to
> set debug_options ALL,0. If you really don't want to know about the
> critical problems that do happen then set filename to /dev/null as well.
>
>> cache_store_log none
>> log_ip_on_direct off
>> hosts_file /etc/hosts
>> refresh_pattern ^ftp: 1440 20% 10080
>> refresh_pattern ^gopher: 1440 0% 1440
>
> without QUERY acl above, you wil need this right here in the pattern order:
> refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
>
>> refresh_pattern . 0 20% 4320
>> quick_abort_min 0 KB
>> quick_abort_max 0 KB
>> range_offset_limit 0 KB
>
> Be careful, but you may want to play at setting these to continue
> downloads. (quick_abort -1 KB)
> That will cause all partial and restarted downloads to become HIT later.
> At risk of some wastage.
>
>> half_closed_clients off
>> shutdown_lifetime 0 seconds
>> acl all src 0.0.0.0/0.0.0.0
>> acl manager proto cache_object
>> acl localhost src 127.0.0.1/255.255.255.255
>> acl to_localhost dst 127.0.0.0/8
>> acl SSL_ports port 443 # https
>> acl SSL_ports port 563 # snews
>> acl SSL_ports port 873 # rsync
>> acl Safe_ports port 80 # http
>> acl Safe_ports port 21 # ftp
>> acl Safe_ports port 443 # https
>> acl Safe_ports port 70 # gopher
>> acl Safe_ports port 210 # wais
>> acl Safe_ports port 1025-65535 # unregistered ports
>> acl Safe_ports port 280 # http-mgmt
>> acl Safe_ports port 488 # gss-http
>> acl Safe_ports port 591 # filemaker
>> acl Safe_ports port 777 # multiling http
>> acl Safe_ports port 631 # cups
>> acl Safe_ports port 873 # rsync
>> acl Safe_ports port 901 # SWAT
>> acl purge method PURGE
>> acl CONNECT method CONNECT
>> acl ReseauLocal src 10.0.0.0/16
>> http_access allow manager localhost
>> http_access deny manager
>> http_access allow purge localhost
>> http_access deny purge
>> http_access allow localhost
>> http_access allow ReseauLocal
>> http_access deny all
>> http_reply_access allow all
>> icp_access deny all
>> cache_effective_group proxy
>> httpd_suppress_version_string on
>> via off
>> forwarded_for off
>> log_icp_queries off
>> client_db off
>> coredump_dir /var/spool/squid
>> pipeline_prefetch off
>> <=
>>
>> Do you see something that need to be improved ? Did I miss something?
>
> Theres a lot of tweaks with refresh_pattern that can be done to warp
> things into cache longer than they are supposed to be stored. I won't
> advocate any though.
>
>
> Amos
> --
> Please be using
> Current Stable Squid 2.7.STABLE5 or 3.0.STABLE11
> Current Beta Squid 3.1.0.3
>

-- 
Matheus
P.O.Box 1402
kampala- Uganda
Tel: +256-752-616056
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